Alkaline hydrothermal treatment of P25 titanium dioxide for low temperature sintering of Li2TiO3 tritium breeding ceramics

Abstract

• The structural properties of Ti sources affect the sintering activity of Li 2 TiO 3 . • P25-AHT is superior to anatase TiO 2 in reducing sintering temperatures of Li 2 TiO 3 . • The prepared Li 2 TiO 3 ceramics have high crushing load and thermal conductivity. For solid tritium breeding materials, a high sintering temperature is essential to achieve satisfactory density, high crushing load, favorable physical and chemical properties, while lithium volatilization and grain coarsening occur at higher sintering temperature, which are not conducive to tritium production and release. Therefore, low temperature sintering of lithium containing ceramics needs to be studied. In this work, P25 titanium dioxide was hydrothermally treated in alkaline solution, and then used as titanium source to prepare Li 2 TiO 3 ceramics. The prepared Li 2 TiO 3 ceramics exhibit uniform and dense microstructure and extremely high crushing load (a.v. 78.93 ∼ 83.98 N) at a relative low sintering temperature (750 ∼ 800 °C). The thermal conductivity of Li 2 TiO 3 ceramic sintered at 800 °C is calculated to be 3.48 W/m•K at room temperature, retaining 2.50 W/m•K at 773 K, which is comparable to the values in literatures. The results suggest the sintering activity of Li 2 TiO 3 is greatly enhanced when alkaline hydrothermally treated P25 is used as titanium source.